All systems
Technical sheet
A.01A.02
SystemS-38

Wood-fibre ETICS

An external insulation system with wood-fibre boards: a dense, breathable bio-based insulant, bonded and anchored to the wall, base-coated with mesh and finished with mineral render. Besides insulating in winter like any system, its high mass shifts the summer heat, keeping the house cool; it is vapour-open and of renewable origin. It is the choice of natural building and summer comfort.

Isolamento a cappotto (ETICS)Bio-based breathable external insulation
B.01
System build-up6 layers
INTERNOESTERNO1. Parete2. Collante3. Pannello in fibra di legno4. Rasatura + rete5. Intonaco minerale6. TinteggiaturaTassello

Technical section of the system, from inside (left) to outside (right).

Bio-based breathable external insulation
Spessore dell'isolante
10-20cm
Conduttività λ
0,038-0,045W/mK
Densità del pannello
110-260kg/m3
Sfasamento termico
8-12h
Reazione al fuoco
B-s1,d0 / E
Permeabilità al vapore (μ)
3-5
Descriptive memo

An external insulation system with wood-fibre boards: a dense, breathable bio-based insulant, bonded and anchored to the wall, base-coated with mesh and finished with mineral render. Besides insulating in winter like any system, its high mass shifts the summer heat, keeping the house cool; it is vapour-open and of renewable origin. It is the choice of natural building and summer comfort.

Wood-fibre ETICS is an external insulation system in which the insulant is a board of pressed wood fibres, dense and renewable. The laying follows the logic of the classic system — bonding, anchoring, reinforced base coat, finish — but the material changes the behaviour: more mass, more breathability, biological origin.

Summer comfort: the time shift

Wood fibre is dense and heavy compared with synthetic insulants: besides slowing the heat flow (insulation), it stores heat and releases it with a delay. This «time shift» of many hours means the afternoon heat reaches the inside in the evening, damped: in summer the house stays cool. It is the quality that sets massive insulants apart from light ones, at the same winter U-value.

Breathable and bio-compatible

Like rock wool, wood fibre is vapour-open: the wall «breathes» and moisture dries, reducing condensation. It is also a material of plant origin, renewable and low-impact, often chosen in natural building for healthiness and a low carbon footprint. The finish must stay vapour-open (mineral renders and paints) so its quality is not lost.

Laying and protection

Wood fibre dislikes prolonged liquid water: on site it must be protected from rain until the base coat, and at the foot the plinth is detailed so it does not get wet. It is heavier than EPS, so adhesives and anchors must be sized accordingly. Reinforced base coat with mesh, corner beads, drips and finish follow the system's rules, with products compatible with the fibrous substrate.

Systems architecture

Why it works

Thermal phase shift · summer comfort
Ttimeoutdoor (sun)indoorphase shift φ ≈ 12 hdense wood fibre delays and flattens the summer heat wave:the indoor peak arrives hours later and much reduced

In winter every external insulation works much the same; the difference shows in summer. Wood fibre is dense and stores a lot of heat, so the heat wave that strikes the wall at midday is delayed by some ten to twelve hours and reaches the inside at night, flattened — when cooler air can vent it away. This «phase shift», together with its openness to vapour and its renewable origin, is why wood fibre is the choice for summer comfort and natural building, where light foams stay hot and let the peak straight through.

Thermal phase shift by insulant (h)

Comparison · insulants
Wood fibre
≈ 12 h
Cork
≈ 10 h
Rock wool
≈ 7 h
EPS
≈ 3 h

Longer bar = more summer comfort. For the same thickness, dense wood fibre delays the heat far longer than light foams: the indoor peak comes at night, flattened.

Nodal details

Critical junctions · sections
123456
D.01
Base course / starting profile

The cappotto starts on an aluminium starting profile fixed to the wall: it sets the line, carries the first row of boards and ends in a drip that throws the water clear. Below it the plinth is insulated with water-resistant XPS, because that band is the most exposed to splashing and rising damp.

  1. Wall
  2. Starting profile (with drip)
  3. Wood-fibre board
  4. Reinforced base coat
  5. Plinth board (XPS) below
  6. Render + finish
123456
D.02
Reinforced base coat and corner

Over the boards a base coat is applied with the glass-fibre mesh embedded in its outer third — never against the board — so it controls the cracking from thermal movement. At corners and openings a PVC bead and a second mesh reinforce the most stressed lines; dowels are set after the adhesive has cured.

  1. Wood-fibre board
  2. Adhesive / base coat
  3. Reinforcing mesh
  4. Corner bead (PVC + mesh)
  5. Dowel (after curing)
  6. Finish render

Installation controls

Specification · checklist

01 · Substrate

Sound, clean, flat wall
Moisture content checked
Adhesion / pull-off test

02 · Bonding & fixing

Adhesive coverage
Dowels after curing
Boards staggered, tight joints

03 · Base coat

Mesh in the outer third
Overlaps and corner beads
No mesh showing through

04 · Render & finish

Mineral, breathable render
Even thickness
Weather window respected

05 · Details

Base profile and drip
Openings reinforced (diagonals)
Sealing at penetrations

Recurring defects

Diagnostics · site
Termo-igrometrica
Swelling of the boards from moisture
CauseWood fibre is hygroscopic: if it is wetted during the works or by a persistent leak, the boards swell and the render telegraphs the joints.
PreventionProtect the boards while building, weather the render in time, flashings and drips, a ventilated, water-resistant plinth.
Meccanica
Cracking of the base coat
CauseThermal movement and shrinkage concentrate at the board joints and openings; a thin or badly placed base coat cracks along them.
PreventionMesh in the outer third, double mesh at openings, boards staggered, tight joints, a render with the right elasticity.
Adesione
Detachment of the boards from the wall
CauseA dusty or uneven substrate, too little adhesive or dowels set too early let the dense, heavy boards detach and bulge.
PreventionSound prepared substrate, adhesive coverage, dowels after curing, number and pattern of dowels to the wind load.
Biologica
Mould and algae on the render
CauseA cold, damp outer surface that dries slowly — north faces, shade, splashing — is colonised by mould and algae.
PreventionBreathable mineral render, generous roof overhangs and drips, ventilation, cleaning, a finish suited to the exposure.

Component materials

The network · materials